Indicate by check mark whether the registrant is an emerging growth
company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of
this chapter). Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to
use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02.

Results of Operations and Financial Condition.

On August 2, 2018, Mediacom
Broadband LLC issued a press release announcing its financial results for the three months ended June 30, 2018. A copy of the press release is being furnished as Exhibit 99.1 to this report and is incorporated herein by reference.

The press release contains disclosure of operating income before depreciation and amortization (OIBDA), free cash flow, and cash
interest expense, which are not financial measures calculated in accordance with generally accepted accounting principles (GAAP) in the United States. Reconciliations of OIBDA, free cash flow and cash interest expense to the most
directly comparable financial measures calculated and presented in accordance with GAAP are presented on Table 2 of the press release. Disclosure regarding managements reasons for presenting these
non-GAAP measures is set forth on Table 4 of the press release.

Revenues were $274.8 million, reflecting a 3.3% increase from the prior year period



Operating income was $68.6 million, reflecting an 8.3% increase from the prior year period



Operating income before depreciation and amortization (OIBDA) was $105.0 million, reflecting a 3.6% increase from the prior year period



Net cash flows provided by operating activities were $85.3 million, compared to $75.3 million in the prior year period



Free cash flow of $47.8 million, compared to $31.0 million in the prior year period

About
Mediacom

Mediacom Communications Corporation is the 5th largest cable operator in the U.S. serving almost 1.4 million customers in smaller
markets primarily in the Midwest and Southeast. Mediacom offers a wide array of information, communications and entertainment services to households
and businesses, including video, high-speed data, phone, and home security and automation. Through
Mediacom Business, the company provides innovative broadband solutions to commercial and public sector customers of all sizes, and sells advertising and production services under the OnMedia brand. More information about Mediacom is available at
www.mediacomcable.com.

Contacts:

Investor Relations

Media Relations

Jack P. Griffin

Thomas J. Larsen

Vice President,

Corporate Finance

Senior Vice President,

Government and Public Relations

(845) 443-2654

(845) 443-2754

*

OIBDA and free cash flow are defined under Use of Non-GAAP Financial Measures in Table 4 and are reconciled to operating income and net cash flows provided by operating activities, respectively, in Table 2.
The effects of recent changes to certain accounting standards on our revenue recognition are noted in Table 5.

TABLE 1*

Mediacom Broadband LLC

Selected Financial and Operating Data

(Dollars in thousands, except per unit data)

(Unaudited)

Three Months Ended June 30,

2018

2017

YoY% Change

Video

$

107,812

$

111,522

(3.3%)

High-speed data

100,023

91,246

9.6%

Phone

15,271

15,049

1.5%

Business services

41,682

37,978

9.8%

Advertising

9,964

10,110

(1.4%)

Total revenues

$

274,752

$

265,905

3.3%

Service costs

(115,267

)

(110,930

)

3.9%

SG&A expenses

(49,102

)

(48,621

)

1.0%

Management fees

(5,350

)

(5,015

)

6.7%

OIBDA (a)

$

105,033

$

101,339

3.6%

Cash interest expense (a)

(12,307

)

(17,074

)

(27.9%)

Capital expenditures

(40,439

)

(48,726

)

(17.0%)

Dividend to preferred members

(4,500

)

(4,500

)



Free cash flow (a)

$

47,787

$

31,039

54.0%

OIBDA margin (b)

38.2

%

38.1

%

June 30,2018

June 30,2017

YoY% Change

Video customers

447,000

459,000

(2.6%)

High-speed data (HSD) customers

690,000

655,000

5.3%

Phone customers

332,000

288,000

15.3%

Primary service units (PSUs)

1,469,000

1,402,000

4.8%

Video customer declines

(6,000

)

(2,000

)

HSD customer increases

11,000

3,000

Phone customer increases

9,000

15,000

Quarterly PSU increases

14,000

16,000

Customer relationships (c)

757,000

754,000

0.4%

Average total monthly revenue per:

PSU (d)

$

62.64

$

63.58

(1.5%)

Customer relationship (e)

$

121.06

$

117.32

3.2%

June 30,2018

June 30,2017

Bank credit facility

$

1,127,500

$

1,014,000

5 1⁄2%
senior notes due 2021

200,000

200,000

6 3⁄8%
senior notes due 2023



300,000

Total debt (f)

$

1,327,500

$

1,514,000

Total leverage ratio (g)

3.16

x

3.73

x

Interest coverage ratio (h)

8.53

x

5.94

x

*

See Table 2 for reconciliations of OIBDA to operating income, cash interest expense to interest expense, net, and free cash flow to net cash flows from operating activities. See Table 3 for details of capital
expenditures. See Table 5 regarding the effect of recent changes to certain accounting standards on our revenue recognition. See footnotes on Page 5, which contain important disclosures regarding the definitions used for
selected unaudited financial and operating data.

Page 2 of 5

TABLE 2

Mediacom Broadband LLC

Reconciliation of Non-GAAP Measures

(Dollars in thousands)

(Unaudited)

Three Months EndedJune 30,

2018

2017

Net cash flows provided by operating activities

$

85,298

$

75,278

Capital expenditures

(40,439

)

(48,726

)

Dividend to preferred members

(4,500

)

(4,500

)

Other expense, net

261

396

Changes in assets and liabilities, net

7,167

8,591

Free cash flow

$

47,787

$

31,039

Operating income

$

68,554

$

63,321

Depreciation and amortization

36,479

38,018

OIBDA

$

105,033

$

101,339

Interest expense, net

$

13,337

$

18,005

Amortization of deferred financing costs

(1,030

)

(931

)

Cash interest expense

$

12,307

$

17,074

TABLE 3

Mediacom Broadband LLC

Capital Expenditures

(Dollars in thousands)

(Unaudited)

Three Months EndedJune 30,

2018

2017

Customer premise equipment

$

17,696

$

21,410

Enterprise networks

2,620

2,840

Scalable infrastructure

6,745

10,359

Line extensions

3,442

5,114

Upgrade / rebuild

5,955

6,604

Support capital

3,981

2,399

Total capital expenditures

$

40,439

$

48,726

Page 3 of 5

TABLE 4

Use of Non-GAAP Financial Measures

OIBDA, cash interest expense and free cash flow are not financial measures calculated in accordance with generally
accepted accounting principles (GAAP) in the United States. We define OIBDA as operating income before depreciation and amortization. We define cash interest expense as interest expense, net, less amortization of deferred financing
costs. We define free cash flow as OIBDA less capital expenditures, cash interest expense and dividends to preferred members.

OIBDA is one of the primary
measures used by management to evaluate our performance and to forecast future results. We believe OIBDA is useful for investors because it enables them to assess our performance in a manner similar to the methods used by management, and provide
measures that can be used to analyze our value and evaluate our performance compared to other companies in the cable industry. A limitation of OIBDA, however, is that it excludes depreciation and amortization, which represents the periodic costs of
certain capitalized tangible and intangible assets used in generating revenues in our business. Management utilizes a separate process to budget, measure and evaluate capital expenditures. OIBDA might not be comparable to similarly titled measures
used by other companies, which may have different depreciation and amortization policies, and are key components in our covenant calculations.

Free cash
flow is used by management to evaluate our ability to repay debt and facilitate the growth of our business with internally generated funds. A limitation of free cash flow, however, is that it may be affected by the timing of our capital spending. We
believe free cash flow is useful for investors as it provides an additional measure that can be used to analyze our value and evaluate our performance compared to other companies in the cable industry. Free cash flow may not be comparable to
similarly titled measures reported by other companies.

OIBDA and free cash flow should not be regarded as alternatives to operating income or net income
as indicators of operating performance, or to the statement of cash flows as measures of liquidity, nor should they be considered in isolation or as substitutes for financial measures prepared in accordance with GAAP. We believe that operating
income is the most directly comparable GAAP financial measure to OIBDA and that net cash flows provided by operating activities is the most directly comparable GAAP financial measure to free cash flow.

Cash interest expense excludes the amortization of financing costs which were paid upon the financing of the relevant debt. We believe cash interest expense
is useful for investors because it enables them to assess our cost of debt for the current period without including the amortization of financing costs that were previously paid. We believe interest expense, net, is the most directly comparable GAAP
financial measure to cash interest expense.

For reconciliations of OIBDA, cash interest expense and free cash flow to their most directly comparable GAAP
financial measures, see Table 2.

Page 4 of 5

TABLE 5

Changes in Accounting Standards  Revenue Recognition

As of January 1, 2018, we adopted Accounting Standards Update No. 2014-09  Revenues from Contracts
with Customers and related guidance (collectively, revenue recognition), which was issued by the Financial Accounting Standards Board. Adoption of this accounting standard affected both the timing of revenue recognition (the timing
change) and the allocation of revenues among video, HSD and phone within our multi-product offerings, in which we offer product bundles at a discount (the allocation change). We adopted this accounting standard using a modified
retrospective transition, and accordingly, the impact of such adoption was reflected in our financial results only for the three months ended June 30, 2018 and prior period results were not restated. The adoption of the new standard did not
have a material impact on the results of operations of Mediacom Broadband LLC for the three months ended June 30, 2018. Excluding the impact of the timing change on Mediacom Broadband LLC, total revenues and OIBDA for the three months ended
June 30, 2018, would have increased 3.3% and 3.4%, respectively. Because of the allocation change, we recorded a decrease in our video revenues and corresponding increases in our HSD and phone revenues. Excluding the overall impact of the
timing change and the allocation change for Mediacom Broadband LLC, video revenues would have decreased 1.3%, HSD revenues would have increased 7.6% and phone revenues would have decreased 0.5% for the three months ended June 30, 2018.

FOOTNOTES:

(a)

See Table 4 for information about our use of Non-GAAP financial measures.

(b)

Represents OIBDA as a percentage of total revenues.

(c)

Represents the total number of customers that receive at least one service, without regard to which service(s) customers purchase.

(d)

Represents average total monthly revenues for the quarter divided by average PSUs for such quarter.

(e)

Represents average total monthly revenues for the quarter divided by average customer relationships for such quarter.

(f)

Total debt excludes the effect of deferred financing costs, net.

(g)

Represents total debt at quarter end divided by annualized OIBDA for the quarter.